Fuel pump



April 22, 1952 B. G. PARSONS 2,593,788-

FUEL PUMP Filed May 4, 1945 3 Sheets-Sheet l INVENTOR. Z6/7 )Va/150751April 22, 1952 Filed May 4, 1945 B. G. PARSONS FUEL PUMP 3 Sheets-Sheet2 Jegrecas- 7705-1222:

El EL 3 Sheets-Sheet 3 B. G. PARSONS FUEL PUMP IN V EN TOR. ,Be/7 6,'774/150275.

BY M @4% vov-e fwn/MEMS.

Filed May 4, 1945 April 22, 1952 Patented Apr. 22, 1952 y OFFICE FUELPUMP Ben G. Parsons, Grosse Pointe, Mich., assigner to Fuel yChargerCorporation, Detroit, Mich., a

corporation of Michigan Application May 4, 1945, Serial No. 591,967

1 Claim.

The present invention relates to improvements in liquid pumping devicesand particularly to fuel injectors for use with internal combustionengines.

It is a primary object of the present invention to provide improvementsin devices of the type mentioned in which improved means are providedfor controlling the amount of liquid delivered during the deliverystroke of the pump plunger. v

A further object of the invention is to provide improvements in devicesof the type mentioned inA which such devices are of a relatively simpleconstruction and may be accurately and quickly produced in massproduction.

yOther objects, advantages, and features of the present invention willbecome more clearly apparent from the following description, thedrawings relating thereto, and from the claim hereinafter set forth.

In the drawings, in which like numerals are used to designate like partsin the different views throughout:

Figure 1 is a side elevational view of a fuel injector embodyingfeatures of the present invention and showing such injector connected toan injector nozzle;

Fig. 2 is an end elevational view of the construction shown in Fig. 1,taken from the right end thereof; f

Fig. 3 is an end elevational view of the structure shown in Fig. l andtaken from the left end thereof;

Fig. 4 is a vertical, cross-sectional view, with parts in elevation, ofthe structure shown in Fig. 1;

Fig. 5 is a cross-sectional view taken substantially along the line 5-5of Fig. 4;

Fig. 6 is a cross-sectional view taken substantially along the line 6-'6of Fig. 4;

Fig. 7 is a developed elevational view of the actuating cam employedwith the structure shown in Fig. 4;

Fig. 8 is a separated or exploded view of certain of the parts making upthe injector assembly, with certain of the parts shown in cross section;

Fig. 9 is a view similar to Fig. 8 and show-ing the remaining parts asthey would be extended from the right end of Fig. 8; Y

Fig. 10 is a cross-sectional View of the actuating cam;

Fig. 11 is an end elevational view of the drive coupling shown in Fig.8;

Fig. 12 is a side elevational view of the plunger shown in Fig. 8, and

Fig. 13 is a diagrammatic view illustrating the operation of thestructure of the present invention.

The structure of the present invention is particularly adapted to beused on vthe type of injector disclosed in the copending application ofBenG. Parsons Serial No. 568,177, filed December 14, 1944, now'PatentNumber 2,405,163, dated August 6, 1946, although the broader aspects ofthe present invention are also applicable to other types of fuelinjectors, such as a single plunger, single cylinder type. The structuredisclosed in the copending application referred to is a single plunger,multi-cylinder type.

The present invention is illustrated in connection with a fuel injectorwhich employs a single cylinder for distributing liquid fuel, such asgasoline, to a multiplicity of internal combustion engine cylinders. Inthe particular embodiment illustrated, the pump is designed todistribute to six cylinders, by way of example. It will be obvious thatit could be constructed to deliver to more or less cylinders.

The fuel injector is generally indicated at l and comprises a plungerbody 2 formed with a central axial bore 3 therethrough. 'I'he pump body2 has formed therein a plurality of radially extending and equallyspaced inlet bores or ports 4 which open into the bore 3. An annular,external recess or groove 5 is formed around the body 2 and communicateswith the outer ends of ports 4. There are six of such ports in theembodiment illustrated.

An inlet tube fitting 6 embraces the pump body 2 around the groove 5 toform an annular inlet chamber therebetween. The fitting 6 has a tubularprojection l thereon to which a flexible tube or conduit may beconnected. The conduit (not shown) leads to the source of fuel supply.

The tting 8 is mounted on the body 2 and has rubber sealing rings 8disposed on opposite sides thereof, one of the rings v3 abutting againsta shoulder formed on the body 2, and the other ring 8 being disposedbetween the adjacent faces of the fitting 6 and a sealing ring nut 9.The n-ut 9 is threaded onto a threaded portion formed on the exteriorsurface of the body 2.

A plurality of annularly spaced discharge passageways or bores I0 arealso formed in the pump body 2, the inner ends of which open into thebore 3. Such openings are in a plane axially spaced from the plane ofthe inlet ports 4. The opposite ends of passageways l0 communicate withaxially extending openings Il formed in a radially projecting, annularflange l2 of the body asesinas 3 2. There are six of the dischargepassageways I in the embodiment illustrated, one for each of the enginecylinders. Such passageways II! are circurnferentially aligned betweenthe inlet ports 4. This relationship is best seen from a comparison ofFigures and 6.

The injector assembly I is adapted to be mounted to the crankcase of theengine, as is disclosed in the above referred to copending application,by means of mounting bolts I3 which are passed through the openings II.A distributor ring or tube ring I4 is disposed between the.

CII

flange I2 and the adjacent face of the crankcase..

Sealing gaskets I5 are disposed between the facing surfaces of the ringI4, the crankcase, and the flange I2. Washers I5' are disposed betweenthe heads of bolts I3 and the adjacent faces of flange I2. The mountingbolts I9 pass through openings formed in the camring I4 and have reducedportions IB, which form, with such openings and the opening I I, anannular chamber into which the corresponding passageways IIJ open andcommunicate.. Y

Distributor tubes or conduits I6, there being one for each cylinder, arexedly mounted on the ring I4 and lead to their respective injectornozzles Il. Such nozzles are of the pressure responsive opening typedisclosed in the copending application of Ben G. Parsons, Serial No.546,352, iiled July 24, 1944, now abandoned, which open to admit 'fluidto the cylinder at a predetermined nozzle opening pressure.

A hollow delivery plunger I8 is rotatably and reciprocably disposedwithin bore 3 and has an opening through the inner end thereof which isin open communication with the bore 3. The space within the hollowplunger is indicated at I9. The plunger I8 is formed with a plurality ofequally spaced inlet openings through the wall thereof adjacent the openend and communicating with chamber I9. There are six of such openings 28in the embodiment illustrated, one corresponding to each of the inlet.ports 4 and having the same equal spacing. The plunger I8 is also formedwith a single delivery opening 2| through the wall thereof whichcommunicates with chamber I9 and which is axially spaced from the ports2l] and disposed circumferentially between two of the ports 20, as bestshown in Figs. 4 and 8. The opening 2I is adapted to register with theinner open ends of ports or passageways Il) in succession, in a mannervthat will become more apparent from the following description, and inthe manner disclosed in the above mentioned application Serial No.568,177.

The plunger I8 is rotated and reciprocated within the bore 3 to eiectdelivery of the fuel through the delivery passageways I0 in succession.The closed end of the plunger I8 has transversely extending tongue 22with a curved end 23. The plunger I8 and tongue 22 project beyond thebore 3 within an enlarged space formed by an integral annular portion 24of the pump body 2.V

A drive coupling 25 is disposed within the flange 24 and has a groove 26formed in one end thereof which receives the tongue 22 therein. Theopposite side of the coupling 25 has av groove 21 formed therein, whichis displaced 90 from the groove 26 and which is adapted to be connectedto the source of power for rotating the coupling 25 as disclosed in theabove mentioned application Serial No. 568,177. The plunger I8 is thusrotated upon rotation of the drive coupling 25. The reduced end 23formed on the tongue 22 is provided so that alignment of the plunger I8within the bore 3 is not disturbed upon rotation of the coupling 25.

The coupling 25 has a pair of diametrically opposed stub axles 28 formedthereon which serve to mount rollers 30. The rollers 30 are retained onthe stub axles 28 by means of snap rings 3 I. The rollers 30 areconstantly held against the cam surface 32 of a cam ring 33. Cam surface32 is designed to eiect proper reciprocation of the plunger I8 uponrotation thereof. in the present instance being designed with six crestsand troughs. The cam ring 33 is mounted within the flange 24 and is heldagainst axial displacement by means of a snap ring 34 which is receivedwithin an annular internal groove formed in the iiange 24. The cam 33 islocated in its proper rotative position by means of a locating pin 35which is received within a groove 36 in flange 24 and projects within anopening formed in the cam ring 33. n

It will thus be seen that upon rotation of the coupling 25 the plungerI8 is caused toV rotate and reciprocate. When the rollers 30 are on thecrests of cam 32, the plunger I8 is at the beginning of the inlet orsuction stroke; and the six inlet openings 4 are overlapped with theinlet openings 20 in the plunger to provide inlet communication with theinterior space I9. At this time, there is no communication between thedistributor openings 2| and any of the passageways I8, since thepassageways I0 are aligned with ports 4 and opening 2I is displaced withrespect to openings 2li.l When the rollers 30 are in the troughs of cam32, the plunger I8 is at the end of the intake stroke and the beginningof the delivery stroke. Further rotation of the plunger I8 brings theopening 2| into communication with one of the passageways III. At thistime the ports 4 are closed oi. There are thus six cycles ofreciprocation of the plunger for each rotation thereof so that for onerotation of the plunger the opening 2I is brought into communicationwith all of the passageways I0 in succession.

A coil spring 38 is disposed within the hollow plunger I8 Vwith one endbearing against a centering button 39, which in turn Vseats within theend of space I9. The opposite end of the spring 38 abuts against ashoulder 40 formed in the body 2 adjacent the end of bore 3. Axialopening 4I communicates the bore 3 with a pressure chamber 42, formed inthe body 2. The bore 4I adjacent the pressure chamber 42 is formed Vwithan annular valve seat 43 and a hollow valve 44 is disposed within thebore 4I. Such valve 44 has an annular tapered portion 45 adapted to seaton valve seat 43. An annular groove 46 is also formed in the valve 44and a pair of diametrically opposed openings 41 are formed through thewall of the valve 44 in the base of recess 46, communicating with theinterior hollow portion of the valve.

The valve is urged toward the valve seat 43 by means of a coil spring48, one end of which bears against the closed end of the valve and theopposite end of which bears against the inner surface of a control nut49. The control nut 49 is threadably received onto an externallythreaded portion of pump body 2. A control lever 50 is xed to the nut 49and may be rotated to control the spring pressure exerted on the valve44 to urge it against its valve seat and to close communication betweenthe bore 3 and chamber 42.' ,A

Passageways 5I are formed in the valve'body .5 2 which communicate withthe chamber 42 and communicate with each of the ports 4, there being oneof such passageways l for each of the ports 4. Thus, when the valve 44is opened, iluid delivered by the plunger I8 will pass through opening41 into chamber 42 and back to the inlet ports through passageways 59.The point at which such valve 44 is opened will thus determine theamount of fuel delivered through opening 2| during the delivery strokeof the plunger |8. If the nut 49 is turned so that pressure exlerted onit by the fuel pressure, built up during the delivery stroke of thepiston I8, is less than the nozzle opening pressure, that is, theopening pressure of injector nozzle l1, all of the fuel delivered byplunger i3 will be returned to the inlet ports through passageways 5|.By adjusting the nut 49, the pressure required to open the valve 44 maybe varied, so that if it is set above nozzle opening pressure, all thefuel will be delivered through the openings 2| and to the cylindersthrough the nozzles.

At any intermediate setting of the nut 49, the valve 44 is opened andfuel is returned through the passageways 5| until nozzle openingpressure is reached. After the plunger develops pressures higher thannozzle opening pressures, the fluid is introduced into the cylindersthrough the nozzles. Thus, by adjusting nut 49, the amount of fueldelivered through the nozzles may be adjustably set. The relationship ofthe different settings of nut 49 to vary the spring pressure incomparison with the nozzle opening pressure is illustrated in Fig. 13.

In the operation of the device above described, and assuming that thenut 49 is set for opening at a pressure above nozzle opening pressure,fuel is constantly supplied through the tube 7 so that there is aconstant supply of fuel within space 5 and Within the inlet ports 4.With the plunger I8 in such a rotative position that the rollers 30 areon the crests of cam 32, the plunger is at the beginning of its intakestroke. As the rollers 30 move toward the troughs of the cam, theplunger 8 moves toward the left, viewing Fig. 4, with the openingsoverlapping and communicating with inlet ports 4. Fuel is thus drawninto the space I9. When the rollers reach the troughs in the cam 32, theplunger is at the end of the intake stroke and at the beginning of thedelivery stroke. Further rotation of the plunger I8 causes the rollersto move to the crests of the cam, and at the beginning of such movementcommunication between openings 20 and 4 is cut oil, and opening 2|communicates with one of the passageways i9 delivering fuel to theinjector nozzle H associated with that passageway through its particularconduit I6. As soon as nozzle opening pressure is reached, fuel is thendelivered through the nozzle to its particular cylinder during thosedegrees of rotation of the plunger while the particular pressure abovenozzle opening pressure is maintained. A uniform charge of fuel is thusdelivered through the opening 2| to the delivery ports 4 in successionas the plunger |3 rotates and reciprocates, for a particular setting ofthe nut 49. The stroke of the piston I8 is constant, but the amount offuel delivered through the nozzle may be adjustably controlled byadjusting the nut 49, which in eiect adjusts the pressure responsiveopening of valve 44.

What is claimed is:

In a fuel pump having a pump body, a longitudinal bore within said body,inlet ports through said body communicating with said bore, deliveryports through said body axially spaced from said inlet ports andcommunicating with said bore, a hollow delivery plunger disposed Withinsaid bore, means in said plunger communicating the interior of saidplunger with the inlet ports, means in said plunger communicating theinterior of the plunger with said delivery ports in succession, means toreciprocate and rotate said plunger to eifect delivery of fuel throughsaid delivery ports in succession, and adjustable pressure responsivevalve means directly communicable with said bore for controlling theamount of fuel delivered through the delivery port in each deliverystroke of the piston.

BEN G. PARSONS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number v Name Date 1,791,600 Onions Feb. 10, 19311,951,340 Bohuslav Mar. 20, 1934 1,974,851 Hurst Sept. 25, 19342,145,379 Vogelei et al. Jan. 31, 1939 2,219,002' Beeh Oct. 22, 19402,286,928 Pipkin, Jr June 16, 1942 2,333,698 Bremser Nov. 9', 19432,351,908 Beeh June 20, 1944 2,357,870 Beeh Sept. 12, 1944

